This article suggests that sleeping for less than seven and a half hours a night can raise the risk of heart disease by up to fours time. On average people in Britain get about seven hours of hours by a third of people in Britain only have five hours of sleep or less. Scientists have blamed the trend towards shorter nights' sleep for increasing the risk of suffering from a heart attack or stroke. The research was based upon studying 1,255 patients with high blood pressure over a period of 23 months. 1,007 people slept for more than 7.5 hours a night and 248 slept for less time. Getting less sleep was associated with a 27% increase in the risk of heart attacks or strokes. Based on this, I think I need more sleep.